Overview

On this site you will find

iPhone/iPad/iPod touch Apps

Information- and help page for various iPhone/iPad/iPod touch apps such as BetterBrain, iDungeon, iAltairHD and EarPlayer.

AltairZ80 Simulator

Download pages for the AltairZ80 simulator which works on Windows, Macintosh, Linux and Zaurus. Also there is rich collection of operating systems including CP/M, programming languages such as Basic, C, Pascal, and application programs (e.g. WordStar and MultiPlan) ready to run on the simulator.

XYZ GeoBench

Download the XYZ GeoBench for Macintosh including Object Pascal source code. The GeoBench is an interactive system featuring algorithm animation for geometric computation.

Other Interests

You can find pictures and information about our travels on Verena's blog.

Prime Proof

Proof of Peter Schorn: Assume there exist only m prime numbers.

Let n = m + 1. For two numbers i and j with 1 ≤ i < j ≤ n, then

gcd[ (n!)i + 1, (n!)j + 1 ] = 1.

Indeed, j = i + d, with 1 ≤ d < n, so

gcd[ (n!)i + 1, (n!)j + 1 ] = gcd[ (n!)i + 1, (n!)d ] = 1.

Therefore the n integers (n!)i + 1 (for i = 1, 2, …, n) are pairwise relatively prime. If p_i is a prime dividing (n!)i + 1, then p₁, p₂, …, p_n are distinct primes with n = m + 1, which is a contradiction [Paulo Ribenboim, The New Book of Prime Number Records, p. 5, Springer-Verlag 1996, 3^rd edition].

www.mathematic.de

de.wikibooks.org

Publications

The DBLP Computer Science Bibliography

www.schorn.ch